What is true of enzymes?
a. they act as catalysts, age for one specific reaction
b. they speed up or slow down any reaction in a living thing
c. they only slow down reactions
d. they only speed up reactions

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

7. describe two strategies that parents can use to cope with stress. 8. describe the three types of childcare available to families. 9. what can parents do to be more involved in their children's education at home and at school? 10. which factors should a parent consider when choosing a childcare option?

Identify the composition of oceanic and continental crystal rocks. in a model of earth’s interior, where would these rocks appear?